Recent Progress on Structures and Photoelectric Properties of Two-Dimensional Materials under High Pressure

Two-dimensional (2D) materials, owing to their outstanding photoelectric properties, have demonstrated significant potential in both fundamental scientific research and future technological applications, including optoelectronics, energy storage, and conversion devices, establishing them as a cutting-edge research field in condensed matter physics and materials science. The distinctive layered structure of 2D materials renders their physical properties highly sensitive to external stimuli. High-pressure technology, serving as an efficient, continuous, and clean tuning tool, enables precise structural control and optimization of the photoelectric properties of 2D materials by compressing atomic distances, strengthening interlayer coupling, and even inducing structural phase transitions. This article focuses on prototypical two-dimensional materials, including graphene, transition metal dichalcogenides (TMDs), and two-dimensional metal halide perovskites. Employing the diamond anvil cell combined with multimodal in situ high-pressure characterization techniques—such as Xray diffraction, Raman spectroscopy, photoluminescence, and electrical transport measurements—we systematically elucidate the effects of high pressure on the structural and photoelectric properties of these materials. Key findings demonstrate that high pressure can induce the transition of graphene from a semimetal to a semiconductor or even a superconducting state, trigger structural phase transitions and semiconductor-to-metal transitions in TMDs such as MoS₂ and WTe₂, and result in pressuredependent bandgap narrowing and marked enhancements of luminescence intensity in two-dimensional perovskites. This work underscores the utility of high-pressure techniques in uncovering the intrinsic correlations between the microstructure and macroscopic properties of twodimensional materials. Furthermore, it discusses the key challenges and opportunities in this emerging research area, providing insights for the development and practical application of novel functional materials.